In high-risk aerospace propulsion systems, nuclear reactors, and high-pressure chemical systems, tubing is the most vulnerable component. For engineers and purchasing managers, the main pain points when sourcing GH4169 (Alloy 718 equivalent) seamless tubing include:
Wall thickness eccentricity: Poor concentricity creates "thin spots," which can become the starting point for failure. At pressures above 700 bar, these thin spots can expand and rupture, leading to catastrophic system failure.
Internal oxidation and impurities: Traditional annealing processes leave a black oxide scale inside the microtube. During use, this scale can peel off, clogging sensitive fuel injectors and high-precision sensors.
At Gnee Alloy, we eliminate these risks. Our high-pressure GH4169 tubing is meticulously designed for absolute reliability, a feat unmatched by other products.
Click to get a GH4169 product quote
AMS 5589 Standard GH4169 (718 Alloy) Seamless Tube Procurement Guide
Gnee Alloy
AMS 5589 Standard GH4169 (718 Alloy) Seamless Tube Procurement Guide
请替换当前内容 We maintain a busy network of forestry and social development staff along with local facilitators in the areas we work.
We maintain a busy network of forestry and social development staff along with local facilitators in the areas we work.
Gnee Alloy
What is the AMS standard for Inconel 718?
AMS 5663 is a standard for Inconel 718 that defines precise solution treatment and aging requirements, thereby giving it specific mechanical properties to meet the demands of demanding applications.
1. GH4169 Pipe Product Overview
| Parameter | Description |
|---|---|
| Material | GH4169 (UNS N07718 / Inconel 718) |
| Product Form | Seamless Tube / Welded Tube |
| Material Type | Wrought Nickel-based Superalloy |
| Strengthening Mechanism | γ″ + γ′ precipitation hardening |
| Manufacturing Process | Cold Drawn / Cold Pilgered |
| Surface Condition | Annealed & Pickled (AP) / Bright Annealed (BA) / As-Drawn |
| Applicable Standards | AMS 5589, AMS 5590, ASTM B983, GB/T 14994 |
| Typical Applications | Aerospace hydraulic lines, fuel systems, high-temperature sensor sheaths, nuclear industry tubing |
| Maximum Service Temperature (Load-Bearing) | 650 – 700°C |
2. Chemical composition of GH4169 pipe (wt%)
| Element | Content (%) | Function |
|---|---|---|
| Nickel (Ni) | 50.0 – 55.0 | Matrix element; high-temperature stability |
| Chromium (Cr) | 17.0 – 21.0 | Oxidation and corrosion resistance |
| Iron (Fe) | Balance (~18-20) | Fe-Ni-Cr base alloy |
| Niobium (Nb) | 4.75 – 5.50 | Core strengthening element – forms γ″ phase (Ni₃Nb) |
| Molybdenum (Mo) | 2.80 – 3.30 | Solid-solution strengthening; creep and pitting resistance |
| Titanium (Ti) | 0.65 – 1.15 | Forms γ′ strengthening phase |
| Aluminum (Al) | 0.20 – 0.80 | Forms γ′ strengthening phase; improves oxidation resistance |
| Carbon (C) | ≤ 0.08 | Low carbon for weldability and toughness |
| Manganese (Mn) | ≤ 0.35 | Deoxidizer |
| Silicon (Si) | ≤ 0.35 | Deoxidizer |
| Phosphorus (P) | ≤ 0.015 | Ensures toughness |
| Sulfur (S) | ≤ 0.015 | Ensures hot workability |
| Boron (B) | 0.002 – 0.006 | Grain boundary strengthener |
| Cobalt (Co) | ≤ 1.00 | Residual element |
| Copper (Cu) | ≤ 0.30 | Residual element |
3. GH4169 pipe physical properties
| Property | Value | Engineering Significance |
|---|---|---|
| Density | 8.19 g/cm³ (0.296 lb/in³) | Weight calculation |
| Melting Range | 1260 – 1336°C (2300-2440°F) | Fire resistance margin |
| Thermal Conductivity (20°C) | 11.4 W/m·K | Heat dissipation |
| Thermal Conductivity (500°C) | ~16.0 W/m·K | High-temperature performance |
| CTE (20-100°C) | 13.0 × 10⁻⁶/°C | Fitting compatibility |
| CTE (20-600°C) | ~14.5 × 10⁻⁶/°C | High-temperature design |
| Specific Heat (20°C) | 435 J/kg·K | Thermal capacity |
| Specific Heat (600°C) | ~500 J/kg·K | High-temperature thermal capacity |
| Modulus of Elasticity (20°C) | ~200 GPa | Stiffness |
| Modulus of Elasticity (600°C) | ~175 GPa | Hot stiffness |
| Electrical Resistivity | 1.25 µΩ·m | – |
| Magnetic Permeability | ~1.005 (slightly magnetic) | – |
Click to download the GH4169 alloy PDF file now
4. GH4169 pipe size specifications
| Parameter | Range | Aerospace Tolerance |
|---|---|---|
| Outside Diameter (OD) | 3.0 mm – 50.8 mm (0.125″ – 2.000″) | ±0.025 – ±0.050 mm |
| Wall Thickness | 0.3 mm – 5.0 mm (0.012″ – 0.200″) | ±5% – ±10% |
| Length | 3000 mm – 12000 mm | ±1 mm |
| OD Ovality | – | ≤ 0.5% of OD |
| Wall Concentricity | – | ≤ 8% of wall thickness |
| Straightness | – | ≤ 0.5 mm/m |
| ID Surface Roughness (Ra) | – | ≤ 0.4 µm (BA condition) |
| OD Surface Roughness (Ra) | – | ≤ 0.4 µm (BA condition) |
Common Tube Sizes
| OD (mm) | OD (in) | Wall (mm) | Wall (in) | Typical Application |
|---|---|---|---|---|
| 3.18 | 0.125 | 0.51 | 0.020 | Instrumentation lines |
| 4.76 | 0.188 | 0.71 | 0.028 | Control lines |
| 6.35 | 0.250 | 0.89 | 0.035 | Fuel lines |
| 6.35 | 0.250 | 1.24 | 0.049 | High pressure fuel |
| 9.53 | 0.375 | 1.07 | 0.042 | Bleed air ducts |
| 9.53 | 0.375 | 1.65 | 0.065 | High pressure bleed air |
| 12.70 | 0.500 | 1.24 | 0.049 | High pressure hydraulic |
| 12.70 | 0.500 | 1.65 | 0.065 | Main hydraulic lines |
| 15.88 | 0.625 | 1.65 | 0.065 | Turbine cooling |
| 15.88 | 0.625 | 2.11 | 0.083 | High pressure cooling |
Contact us to customize GH4169 products to fit your project dimensions
5. GH4169 Non-destructive Testing (NDT) for Pipelines
| Test Method | Requirement | Standard | Acceptance Criteria |
|---|---|---|---|
| Eddy Current Testing (ET) | 100% | ASTM E426 | No relevant indications |
| Ultrasonic Testing (UT) | As specified (wall ≥ 0.5mm) | ASTM E213 | No defects exceeding 5% wall |
| Hydrostatic Test | 100% | ASME Section VIII | 1.5× working pressure, no leakage |
| Helium Leak Test | As specified | ASTM E498 | ≤ 1 × 10⁻⁹ std cc/sec |
| Visual Inspection | 100% (10-30x magnification) | ASTM E543 | No surface defects |
| Borescope Inspection | 100% (small diameters) | – | Smooth, clean ID |
6. Technical performance of GH4169 pipe compared to other industrial pipes
| Quality Feature | Standard Industrial Pipe | Our Premium GH4169 Tube | Industrial Advantage |
| Wall Concentricity | Deviation ≤ 10-15% | Deviation ≤ 5% | Maximizes safety factor at 700 bar. |
| Internal Finish | Pickled (Gray/Dull) | Bright Annealed (BA) | Zero Oxidation Scale; protects sensors. |
| Tolerance Class | h11 - h12 | h8 - h10 | Ready for automated precision assembly. |
| Testing (NDT) | Visual / Hydrostatic | 100% UT & Eddy Current | Guaranteed Zero Defect integrity. |
7. Advantages of Gnee Alloy GH4169 Pipe VIM + VAR
The performance of pressure tubes stems from in-furnace melting. Our GH4169 (UNS N07718) is manufactured using a dual vacuum melting process:
VIM + VAR process
Vacuum Induction Melting (VIM): Removes dissolved gases and volatile impurities, resulting in a pure chemical matrix.
Vacuum Arc Remelting (VAR): Ensures extremely high chemical homogeneity and eliminates macroscopic segregation (spots) that lead to fatigue failure.
Compliance: Fully compliant with AMS 5589, AMS 5590, and ASTM B637 standards.
8. GH4169 Alloy Pipe Industrial Applications
As a Reliable Supplier, we provide certified tubing for the world's most demanding environments:
Aero-engine Fuel Lines: Handling high-pressure aviation fuel at temperatures up to 700°C.
Hydraulic Actuator Tubing: Maintaining precision tolerances in high-vibration flight control systems.
Nuclear Reactor Instrumentation: High-strength structural conduit requiring elite Industrial Durability.
Common-Rail Fuel Injection: Precision capillary tubes for high-performance diesel and turbine engines.
Why Choose Gnee as Your Nickel-Based Alloy Supplier
✅️Direct Factory Price: Eliminate the 15-20% trading markup and buy directly from the specialized superalloy mill.
✅️MTC 3.1 Traceability: Full heat-analysis and mechanical property verification documented with every batch.
✅️Wholesale Inventory: We maintain a large stock of standard Sch 40 and Sch 80 seamless pipes for Fast Global Shipping.
✅️Custom Fabrication: We offer precision Cut-to-Length, deburring, and specialized end-forming to match your CAD blueprints.
Gnee Alloy GH4169(inconel 718) Certificate
📦 Packaging and Shipping
All Nickel Based Alloy products are packaged using the following methods:
Wooden pallets or crates
Moisture-proof packaging
Labels with furnace number, standard, and size labels
Shipped worldwide by sea, air, or express
Gnee Alloy GH4169 Product Packing
Contact us for the latest export price quote for GH4169 Alloy
FAQ
Q1: Is your GH4169 tube equivalent to Inconel 718?
A: Yes. GH4169 is the technical equivalent designation used in international blueprints for UNS N07718. Our material is globally interchangeable for all aerospace and nuclear energy applications.
Q2: How do you guarantee the internal cleanliness of small capillary tubes?
A: We utilize Vacuum Bright Annealing (BA). By heating the tubes in a high-purity hydrogen atmosphere, we prevent oxygen from ever touching the metal, ensuring the internal diameter (ID) is as bright as a mirror.
Q3: Can GH4169 handle cryogenic temperatures as well as heat?
A: Absolutely. GH4169 is a rare alloy that maintains exceptional toughness and ductility down to -253°C, making it ideal for liquid hydrogen fuel systems in space exploration.
Q4: Do you offer bulk discounts for MRO (Maintenance, Repair, and Overhaul) programs?
A: Yes. We support long-term aerospace MRO contracts with attractive Wholesale Pricing and priority scheduling for recurring orders.
